a = fibonacci(45)
function s = fibonacci(n)
    f[1] = 0;f[2] = 1;
    for i = 3:n
        f(i) = f(i-1) + f(i-2);
    end
        return f(i);
    end

    
    function s = mylog(a)
    if a == 0
        = find(a = 0)
        s = 0;
   
    elseif a > 0
        s = log(a);
    end     
end
function s=mylog(a) 
    [mm,nn] = size(a);
    ii= zeros(mm*nn,1);
    jj = zeros(mm*nn,1);
    [ii,jj] = find(a==0);
if ii(1)==0&&jj(1)==0
   
    s = log(a);
else
    
    kk=1;
    for i = 1:mm
        for j=1:nn
               if i ==ii(kk)&&j ==jj(kk)
                   s(i,j) = 0;
                   kk = kk+1;
               else
                   s(i,j) = log(a(i,j))
               end
        end
    end
       
end
end


